This paper presents the chronological development of Gulf of Suez Petroleum Co. (GUPCO) offshore well completions. Reservoir depletion and the problems experienced with the initial completions problems experienced with the initial completions prompted the need for basic changes. Several prompted the need for basic changes. Several changes in completion systems were studied before an optimum solution was selected. The development includes all the areas of original completions that had shown operational shortcomings: the completion-fluids design and selection, down hole equipment, running and pulling operations, wireline phase, perforating, pulling operations, wireline phase, perforating, and initial flow phase. All the changes interacted and resulted in the completion optimization which have considerably reduced operations time and cost, significantly reduced operational problems, and increased well productivity. It worth to note that, as a result productivity. It worth to note that, as a result of completion optimization, now a completion job takes less than one half of the time that was spent to complete one well ten years ago.
Gulf of Suez Petroleum Company (GUPCO) is the largest offshore oil producer in Egypt. GUPCO began offshore production in late 1967 from EL-MORGAN field. Now, production in the Gulf of Suez is from 50 sandstone reservoirs between 5500 ft. and 11500 ft. subsea. The initial reservoir pressure ranged from 2600 psi. to 5900 psi, - the current reservoir psi. to 5900 psi, - the current reservoir pressure ranging from 500 to 4500 psi. In pressure ranging from 500 to 4500 psi. In 1988, the production rate is approximately 450,000 BOPD from 50 offshore producing platforms containing over 300 wells. Some of platforms containing over 300 wells. Some of these wells produce naturally, but the majority requires an artificial lift system. Gas lift is the most common method of artificial lift in Gulf of Suez.
The original completion systems and practices used in early development wells were subject to continuous review and changes. Alternative designs were evaluated according to their impact on the completion time, workover plans, suitability to production policies, and safety. Although historically the changes in each one of the completion areas were made seperately, the net result is that all changes interacted to produce significant operational gains. As a result of the optimization efforts, the changes in completion operations effected the following major improvements:
Replacement of mudline packers by mud-line hangers, then by well-head tubing hangers,
Generalization of the use of hydraulic-set packers,
Elimination of dual-string packers,
Elimination of dual-string completions,
Generalization of tubing conveyed perforating technique,
Utilization of tubing retrievable sub-surface safety valves,
Quasi-elimination of wireline operations,
Standardization of tubing sizes, threads, and connections,
Control of corrosion and scale, and
Standardization of completion fluids.
All these changes were made compatible with GUPCO basic casing programs and production policies. Moreover, programs and production policies. Moreover, the changes comply with the safety regulations in offshore oil fields. Definite signs of improvement were noticed after applying each of these major changes.
This paper presents the background information for each item, explains how the current optimum solution for the completion problems were reached, and documents how these and other minor changes have resulted in the completion optimization.
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